## Overview
Updates `eslint-plugin-jest` and enables the recommended rules with some
turned off that are unhelpful.
The main motivations is:
a) we have a few duplicated tests, which this found an I deleted
b) making sure we don't accidentally commit skipped tests
## Overview
Reverts https://github.com/facebook/react/pull/26616 and implements the
suggested way instead.
This change in #26616 broken the internal sync command, which now
results in duplicated `@generated` headers. It also makes it harder to
detect changes during the diff train sync. Instead, we will check for
changes, and if there are changes sign the files and commit them to the
sync branch.
## Strategy
The new sync strategy accounts for the generated headers during the
sync:
- **Revert Version**: Revert the version strings
- **Revert @generated**: Re-sign the files (will be the same hash as
before if unchanged)
- **Check**: Check if there are changes **if not, skip**
- **Re-apply Version**: Now add back the new version string
- **Re-sign @generated**: And re-generate the headers
Then commit to branch. This ensures that if there are no changes, we'll
skip.
---------
Co-authored-by: Timothy Yung <yungsters@gmail.com>
The goal is to improve speed of the development by inlining and DCE
unused branches.
We have the ability to preserve some variable names and pretty print in
the production version so might as well do the same with DEV.
Stacked on #29491
Previously if you aborted during a render the currently rendering task
would itself be aborted which will cause the entire model to be replaced
by the aborted error rather than just the slot currently being rendered.
This change updates the abort logic to mark currently rendering tasks as
aborted but allowing the current render to emit a partially serialized
model with an error reference in place of the current model.
The intent is to support aborting from rendering synchronously, in
microtasks (after an await or in a .then) and in lazy initializers. We
don't specifically support aborting from things like proxies that might
be triggered during serialization of props
While most builds of Flight and Fizz schedule work in new tasks some do
execute work synchronously. While this is necessary for legacy APIs like
renderToString for modern APIs there really isn't a great reason to do
this synchronously.
We could schedule works as microtasks but we actually want to yield so
the runtime can run events and other things that will unblock additional
work before starting the next work loop.
This change updates all non-legacy uses to be async using the best
availalble macrotask scheduler.
Browser now uses postMessage
Bun uses setTimeout because while it also supports setImmediate the
scheduling is not as eager as the same API in node
the FB build also uses setTimeout
This change required a number of changes to tests which were utilizing
the sync nature of work in the Browser builds to avoid having to manage
timers and tasks. I added a patch to install MessageChannel which is
required by the browser builds and made this patched version integrate
with the Scheduler mock. This way we can effectively use `act` to flush
flight and fizz work similar to how we do this on the client.
## Overview
We didn't have any tests that ran in persistent mode with the xplat
feature flags (for either variant).
As a result, invalid test gating like in
https://github.com/facebook/react/pull/29664 were not caught.
This PR adds test flavors for `ReactFeatureFlag-native-fb.js` in both
variants.
Use some clever git diffing to ignore lines that only change the
`@generated` header. We can't do this for the version string because the
version string can be embedded in lines with other changes, but this
header is always on one line.
RC releases are a special kind of prerelease build because unlike
canaries we shouldn't publish new RCs from any commit on `main`, only
when we intentionally bump the RC number. But they are still prerelases
— like canary and experimental releases, they should use exact version
numbers in their dependencies (no ^).
We only need to generate these builds during the RC phase, i.e. when the
canary channel label is set to "rc".
Example of resulting package.json output:
```json
{
"name": "react-dom",
"version": "19.0.0-rc.0",
"dependencies": {
"scheduler": "0.25.0-rc.0"
},
"peerDependencies": {
"react": "19.0.0-rc.0"
}
}
```
https://react-builds.vercel.app/prs/29736/files/oss-stable-rc/react-dom/package.json
Host Components can exist as four semantic types
1. regular Components (Vanilla obv)
2. singleton Components
2. hoistable components
3. resources
Each of these component types have their own rules related to mounting
and reconciliation however they are not direclty modeled as their own
unique fiber type. This is partly for code size but also because
reconciling the inner type of these components would be in a very hot
path in fiber creation and reconciliation and it's just not practical to
do this logic check here.
Right now we have three Fiber types used to implement these 4 concepts
but we probably need to reconsider the model and think of Host
Components as a single fiber type with an inner implementation. Once we
do this we can regularize things like transitioning between a resource
and a regular component or a singleton and a hoistable instance. The
cases where these transitions happen today aren't particularly common
but they can be observed and currently the handling of these transitions
is incomplete at best and buggy at worst. The most egregious case is the
link type. This can be a regular component (stylesheet without
precedence) a hoistable component (non stylesheet link tags) or a
resource (stylesheet with a precedence) and if you have a single jsx
slot that tries to reconcile transitions between these types it just
doesn't work well.
This commit adds an error for when a Hoistable goes from Instance to
Resource. Currently this is only possible for `<link>` elements going to
and from stylesheets with precedence. Hopefully we'll be able to remove
this error and implement as an inner type before we encounter new
categories for the Hoistable types
detecting type shifting to and from regular components is harder to do
efficiently because we don't want to reevaluate the type on every update
for host components which is currently not required and would add
overhead to a very hot path
singletons can't really type shift in their one practical implementation
(DOM) so they are only a problem in theroy not practice
Requires https://github.com/facebook/react/pull/29706
The strategy here is to:
- Checkout the builds/facebook-www branch
- Read the current sync'd VERSION
- Checkout out main and sync new build
- sed/{new version string}/{old version string}
- Run git status, skip sync if clean
- Otherwise, sed/{old version string}/{new version string} and push
commit
This means that:
- We're using the real version strings from the builds
- We are checking the last commit on the branch for the real last
version
- We're skipping any commits that won't result in changes
- ???
- Profit!
`disableDOMTestUtils` and the FB build `ReactTestUtilsFB` allowed us to
finish migrating internal callsites off of ReactTestUtils. Now that
usage is cleaned up, we can remove the flag, build artifact, and test
coverage for the deprecated utility methods.
Throw an error during module initialization if the version of the
"react-dom" package does not match the version of "react".
We used to be more relaxed about this, because the "react" package
changed so infrequently. However, we now have many more features that
rely on an internal protocol between the two packages, including Hooks,
Float, and the compiler runtime. So it's important that both packages
are versioned in lockstep.
Before this change, a version mismatch would often result in a cryptic
internal error with no indication of the root cause.
Instead, we will now compare the versions during module initialization
and immediately throw an error to catch mistakes as early as possible
and provide a clear error message.
This one should be fully behind the `enableOwnerStacks` flag.
Instead of printing the parent Component stack all the way to the root,
this now prints the owner stack of every JSX callsite. It also includes
intermediate callsites between the Component and the JSX call so it has
potentially more frames. Mainly it provides the line number of the JSX
callsite. In terms of the number of components is a subset of the parent
component stack so it's less information in that regard. This is usually
better since it's more focused on components that might affect the
output but if it's contextual based on rendering it's still good to have
parent stack. Therefore, I still use the parent stack when printing DOM
nesting warnings but I plan on switching that format to a diff view
format instead (Next.js already reformats the parent stack like this).
__Follow ups__
- Server Components show up in the owner stack for client logs but logs
done by Server Components don't yet get their owner stack printed as
they're replayed. They're also not yet printed in the server logs of the
RSC server.
- Server Component stack frames are formatted as the server and added to
the end but this might be a different format than the browser. E.g. if
server is running V8 and browser is running JSC or vice versa. Ideally
we can reformat them in terms of the client formatting.
- This doesn't yet update Fizz or DevTools. Those will be follow ups.
Fizz still prints parent stacks in the server side logs. The stacks
added to user space `console.error` calls by DevTools still get the
parent stacks instead.
- It also doesn't yet expose these to user space so there's no way to
get them inside `onCaughtError` for example or inside a custom
`console.error` override.
- In another follow up I'll use `console.createTask` instead and
completely remove these stacks if it's available.
This lets us expose the component stack to the error reporting that
happens here as `console.error` patching. Now if you just call
`console.error` in the error handlers it'll get the component stack
added to the end by React DevTools.
However, unfortunately this happens a little too late so the Fiber will
be disconnected with its `.return` pointer set to null already. So it'll
be too late to extract a parent component stack from but you can at
least get the stack from source to error boundary. To work around this I
manually add the parent component stack in our default handlers when
owner stacks are off. We could potentially fix this but you can also
just include it yourself if you're calling `console.error` and it's not
a problem for owner stacks.
This is not a problem for owner stacks because we'll still have those
and so for those just calling `console.error` just works. However, the
main feature is that by letting React add them, we can switch to using
native error stacks when available.
Stacked on #28997.
We can use the technique of referencing an object by its row + property
name path for temporary references - like we do for deduping. That way
we don't need to generate an ID for temporary references. Instead, they
can just be an opaque marker in the slot and it has the implicit ID of
the row + path.
Then we can stash all objects, even the ones that are actually available
to read on the server, as temporary references. Without adding anything
to the payload since the IDs are implicit. If the same object is
returned to the client, it can be referenced by reference instead of
serializing it back to the client. This also helps preserve object
identity.
We assume that the objects are immutable when they pass the boundary.
I'm not sure if this is worth it but with this mechanism, if you return
the `FormData` payload from a `useActionState` it doesn't have to be
serialized on the way back to the client. This is a common pattern for
having access to the last submission as "default value" to the form
fields. However you can still control it by replacing it with another
object if you want. In MPA mode, the temporary references are not
configured and so it needs to be serialized in that case. That's
required anyway for hydration purposes.
I'm not sure if people will actually use this in practice though or if
FormData will always be destructured into some other object like with a
library that turns it into typed data, and back. If so, the object
identity is lost.
This is the first step to experimenting with a new type of stack traces
behind the `enableOwnerStacks` flag - in DEV only.
The idea is to generate stacks that are more like if the JSX was a
direct call even though it's actually a lazy call. Not only can you see
which exact JSX call line number generated the erroring component but if
that's inside an abstraction function, which function called that
function and if it's a component, which component generated that
component. For this to make sense it really need to be the "owner" stack
rather than the parent stack like we do for other component stacks. On
one hand it has more precise information but on the other hand it also
loses context. For most types of problems the owner stack is the most
useful though since it tells you which component rendered this
component.
The problem with the platform in its current state is that there's two
ways to deal with stacks:
1) `new Error().stack`
2) `console.createTask()`
The nice thing about `new Error().stack` is that we can extract the
frames and piece them together in whatever way we want. That is great
for constructing custom UIs like error dialogs. Unfortunately, we can't
take custom stacks and set them in the native UIs like Chrome DevTools.
The nice thing about `console.createTask()` is that the resulting stacks
are natively integrated into the Chrome DevTools in the console and the
breakpoint debugger. They also automatically follow source mapping and
ignoreLists. The downside is that there's no way to extract the async
stack outside the native UI itself so this information cannot be used
for custom UIs like errors dialogs. It also means we can't collect this
on the server and then pass it to the client for server components.
The solution here is that we use both techniques and collect both an
`Error` object and a `Task` object for every JSX call.
The main concern about this approach is the performance so that's the
main thing to test. It's certainly too slow for production but it might
also be too slow even for DEV.
This first PR doesn't actually use the stacks yet. It just collects them
as the first step. The next step is to start utilizing this information
in error printing etc.
For RSC we pass the stack along across over the wire. This can be
concatenated on the client following the owner path to create an owner
stack leading back into the server. We'll later use this information to
restore fake frames on the client for native integration. Since this
information quickly gets pretty heavy if we include all frames, we strip
out the top frame. We also strip out everything below the functions that
call into user space in the Flight runtime. To do this we need to figure
out the frames that represents calling out into user space. The
resulting stack is typically just the one frame inside the owner
component's JSX callsite. I also eagerly strip out things we expect to
be ignoreList:ed anyway - such as `node_modules` and Node.js internals.
This follows the same principle as in #28611.
We cannot serialize Blobs of a form data into HTML because you can't
initialize a file input to some value. However the serialization of
state in an Action can contain blobs. In this case we do error but
outside the try/catch that recovers to error to client replaying instead
of MPA mode. This errors earlier to ensure that this works.
Testing this is a bit annoying because JSDOM doesn't have any of the
Blob methods but the Blob needs to be compatible with FormData and the
FormData needs to be compatible with `<form>` nodes in these tests. So I
polyfilled those in JSDOM with some hacks.
A possible future enhancement would be to encode these blobs in a base64
mode instead and have some way to receive them on the server. It's just
a matter of layering this. I think the RSC layer's `FORM_DATA`
implementation can pass some flag to encode as base64 and then have
decodeAction include some way to parse them. That way this case would
work in MPA mode too.
In order to integrate the `react-reconciler` build created in #28880
with third party libraries, we need to have matching
`react-reconciler/constants` to go with it.
Bundle config: inline internal hook wrapper
Instead of reading this wrapper from 2 files for "start" and "end" and
then string modifying the templates, just inline them like the other
wrappers in this file.
## Summary
The `react-devtools-fusebox` private package is used in the React Native
DevTools (Fusebox) frontend by checking build artifacts into RN's
[fork]([`facebookexperimental/rn-chrome-devtools-frontend`](https://github.com/facebookexperimental/rn-chrome-devtools-frontend))
of the Chrome DevTools (CDT) repo - see
https://github.com/facebookexperimental/rn-chrome-devtools-frontend/pull/22.
Currently, the CDT fork also includes a [manually written TypeScript
definition
file](1d5f8d5209/front_end/third_party/react-devtools/package/frontend.d.ts)
which describes `react-devtools-fusebox`'s API. This PR moves that file
into the React repo, next to the implementation of
`react-devtools-fusebox`, so we can update it atomically with changes to
the package.
As this is the first bit of TypeScript in this repo, the PR adds minimal
support for formatting `.d.ts` files with Prettier. It also opts out
`react-devtools-fusebox/dist/` from linting/formatting as a drive-by
fix.
For now, we'll just maintain the `.d.ts` file manually, but we could
consider leveraging
[`flow-api-translator`](https://www.npmjs.com/package/flow-api-translator)
to auto-generate it in the future.
## How did you test this change?
Build `react-devtools-fusebox`, observe that `dist/frontend.d.ts`
exists.
This PR reorganizes the `react-dom` entrypoint to only pull in code that
is environment agnostic. Previously if you required anything from this
entrypoint in any environment the entire client reconciler was loaded.
In a prior release we added a server rendering stub which you could
alias in server environments to omit this unecessary code. After landing
this change this entrypoint should not load any environment specific
code.
While a few APIs are truly client (browser) only such as createRoot and
hydrateRoot many of the APIs you import from this package are only
useful in the browser but could concievably be imported in shared code
(components running in Fizz or shared components as part of an RSC app).
To avoid making these require opting into the client bundle we are
keeping them in the `react-dom` entrypoint and changing their
implementation so that in environments where they are not particularly
useful they do something benign and expected.
#### Removed APIs
The following APIs are being removed in the next major. Largely they
have all been deprecated already and are part of legacy rendering modes
where concurrent features of React are not available
* `render`
* `hydrate`
* `findDOMNode`
* `unmountComponentAtNode`
* `unstable_createEventHandle`
* `unstable_renderSubtreeIntoContainer`
* `unstable_runWithPrioirty`
#### moved Client APIs
These APIs were available on both `react-dom` (with a warning) and
`react-dom/client`. After this change they are only available on
`react-dom/client`
* `createRoot`
* `hydrateRoot`
#### retained APIs
These APIs still exist on the `react-dom` entrypoint but have normalized
behavior depending on which renderers are currently in scope
* `flushSync`: will execute the function (if provided) inside the
flushSync implemention of FlightServer, Fizz, and Fiber DOM renderers.
* `unstable_batchedUpdates`: This is a noop in concurrent mode because
it is now the only supported behavior because there is no legacy
rendering mode
* `createPortal`: This just produces an object. It can be called from
anywhere but since you will probably not have a handle on a DOM node to
pass to it it will likely warn in environments other than the browser
* preloading APIS such as `preload`: These methods will execute the
preload across all renderers currently in scope. Since we resolve the
Request object on the server using AsyncLocalStorage or the current
function stack in practice only one renderer should act upon the
preload.
In addition to these changes the server rendering stub now just rexports
everything from `react-dom`. In a future minor we will add a warning
when using the stub and in the next major we will remove the stub
altogether
We have changed the shape (and the runtime) of React Elements. To help
avoid precompiled or inlined JSX having subtle breakages or deopting
hidden classes, I renamed the symbol so that we can early error if
private implementation details are used or mismatching versions are
used.
Why "transitional"? Well, because this is not the last time we'll change
the shape. This is just a stepping stone to removing the `ref` field on
the elements in the next version so we'll likely have to do it again.
This disables symbol renaming in production builds. The original
variable and function names are preserved. All other forms of
compression applied by Closure (dead code elimination, inlining, etc)
are unchanged — the final program is identical to what we were producing
before, just in a more readable form.
The motivation is to make it easier to debug React issues that only
occur in production — the same reason we decided to start shipping
sourcemaps in #28827 and #28827.
However, because most apps run their own minification step on their npm
dependencies, it's not necessary for us to minify the symbols before
publishing — it'll be handled the app, if desired.
This is the same strategy Meta has used to ship React for years. The
React build itself has unminified symbols, but they get minified as part
of Meta's regular build pipeline.
Even if an app does not minify their npm dependencies, gzip covers most
of the cost of symbol renaming anyway.
This saves us from having to ship sourcemaps, which means even apps that
don't have sourcemaps configured will be able to debug the React build
as easily as they would any other npm dependency.
Meta uses various tools built on top of the "react-reconciler" package
but that package needs to match the version of the "react" package.
This means that it should be synced at the same time. However, more than
that the feature flags between the "react" package and the
"react-reconciler" package needs to line up. Since FB has custom feature
flags, it can't use the OSS version of react-reconciler.
In #26446 we started publishing non-minified versions of our production
build artifacts, along with source maps, for easier debugging of React
when running in production mode.
The way it's currently set up is that these builds are generated
*before* Closure compiler has run. Which means it's missing many of the
optimizations that are in the final build, like dead code elimination.
This PR changes the build process to run Closure on the non-minified
production builds, too, by moving the sourcemap generation to later in
the pipeline.
The non-minified builds will still preserve the original symbol names,
and we'll use Prettier to add back whitespace. This is the exact same
approach we've been using for years to generate production builds for
Meta.
The idea is that the only difference between the minified and non-
minified builds is whitespace and symbol mangling. The semantic
structure of the program should be identical.
To implement this, I disabled symbol mangling when running Closure
compiler. Then, in a later step, the symbols are mangled by Terser. This
is when the source maps are generated.
In React 19 React will finally stop publishing UMD builds. This is
motivated primarily by the lack of use of UMD format and the added
complexity of maintaining build infra for these releases. Additionally
with ESM becoming more prevalent in browsers and services like esm.sh
which can host React as an ESM module there are other options for doing
script tag based react loading.
This PR removes all the UMD build configs and forks.
There are some fixtures that still have references to UMD builds however
many of them already do not work (for instance they are using legacy
features like ReactDOM.render) and rather than block the removal on
these fixtures being brought up to date we'll just move forward and fix
or removes fixtures as necessary in the future.
This adds support in Flight for serializing four kinds of streams:
- `ReadableStream` with objects as a model. This is a single shot
iterator so you can read it only once. It can contain any value
including Server Components. Chunks are encoded as is so if you send in
10 typed arrays, you get the same typed arrays out on the other side.
- Binary `ReadableStream` with `type: 'bytes'` option. This supports the
BYOB protocol. In this mode, the receiving side just gets `Uint8Array`s
and they can be split across any single byte boundary into arbitrary
chunks.
- `AsyncIterable` where the `AsyncIterator` function is different than
the `AsyncIterable` itself. In this case we assume that this might be a
multi-shot iterable and so we buffer its value and you can iterate it
multiple times on the other side. We support the `return` value as a
value in the single completion slot, but you can't pass values in
`next()`. If you want single-shot, return the AsyncIterator instead.
- `AsyncIterator`. These gets serialized as a single-shot as it's just
an iterator.
`AsyncIterable`/`AsyncIterator` yield Promises that are instrumented
with our `.status`/`.value` convention so that they can be synchronously
looped over if available. They are also lazily parsed upon read.
We can't do this with `ReadableStream` because we use the native
implementation of `ReadableStream` which owns the promises.
The format is a leading row that indicates which type of stream it is.
Then a new row with the same ID is emitted for every chunk. Followed by
either an error or close row.
`AsyncIterable`s can also be returned as children of Server Components
and then they're conceptually the same as fragment arrays/iterables.
They can't actually be used as children in Fizz/Fiber but there's a
separate plan for that. Only `AsyncIterable` not `AsyncIterator` will be
valid as children - just like sync `Iterable` is already supported but
single-shot `Iterator` is not. Notably, neither of these streams
represent updates over time to a value. They represent multiple values
in a list.
When the server stream is aborted we also close the underlying stream.
However, closing a stream on the client, doesn't close the underlying
stream.
A couple of possible follow ups I'm not planning on doing right now:
- [ ] Free memory by releasing the buffer if an Iterator has been
exhausted. Single shots could be optimized further to release individual
items as you go.
- [ ] We could clean up the underlying stream if the only pending data
that's still flowing is from streams and all the streams have cleaned
up. It's not very reliable though. It's better to do cancellation for
the whole stream - e.g. at the framework level.
- [ ] Implement smarter Binary Stream chunk handling. Currently we wait
until we've received a whole row for binary chunks and copy them into
consecutive memory. We need this to preserve semantics when passing
typed arrays. However, for binary streams we don't need that. We can
just send whatever pieces we have so far.
This hasn't been updated in a long time, and it getting really large.
You can view the authors locally via the git history with:
``
git shortlog -se | perl -spe 's/^\s+\d+\s+//'
``
## Overview
**Internal React repo tests only**
Depends on https://github.com/facebook/react/pull/28710
Adds three new assertions:
- `assertConsoleLogDev`
- `assertConsoleWarnDev`
- `assertConsoleErrorDev`
These will replace this pattern:
```js
await expect(async () => {
await expect(async () => {
await act(() => {
root.render(<Fail />)
});
}).toThrow();
}).toWarnDev('Warning');
```
With this:
```js
await expect(async () => {
await act(() => {
root.render(<Fail />)
});
}).toThrow();
assertConsoleWarnDev('Warning');
```
It works similar to our other `assertLog` matchers which clear the log
and assert on it, failing the tests if the log is not asserted before
the test ends.
## Diffs
There are a few improvements I also added including better log diffs and
more logging.
When there's a failure, the output will look something like:
<img width="655" alt="Screenshot 2024-04-03 at 11 50 08 AM"
src="https://github.com/facebook/react/assets/2440089/0c4bf1b2-5f63-4204-8af3-09e0c2d752ad">
Check out the test suite for snapshots of all the failures we may log.
Based on:
- #28804
---
This sets adds a new ReactDOM export called requestFormReset, including
setting up the export and creating a method on the internal ReactDOM
dispatcher. It does not yet add any implementation.
Doing this in its own commit for review purposes.
The API itself will be explained in the next PR.
Previously if the external runtime was enabled Fizz tests would use it
exclusively. However now that this flag is enabled for OSS and Meta
builds this means we were no longer testing the inline script runtime.
This changes the test flags to produce some runs where we test the
inline script runtime and others where we test the external runtime
the external runtime will be tested if the flag is enabled and
* Meta Builds: variant is true
* OSS Builds: experiemental is true
this gives us decent coverage. long term we should probably bring
variant to OSS builds since we will eventually want to test both modes
even when the external runtime is stable.
